Free tool · Late fee calculator
UK late payment interest, to the day.
Statutory interest and the fixed sum on late business invoices, under the Late Payment of Commercial Debts (Interest) Act 1998. One invoice or several, each at the rate for the half year it fell overdue, and a claim letter to print.
- 11.75% a year On invoices overdue from 1 July to 31 December 2026: 8% over the Bank of England's 3.75%
- £40, £70 or £100A fixed sum for each late invoice, by its size
- No clause neededOn business-to-business invoices, unless your contract sets a different rate of interest
Calculator
How statutory interest is worked out
Statutory interest is simple interest at 8% a year over the Bank of England reference rate, counted for each day the invoice is late, plus a fixed sum for each late invoice. It's the rate GOV.UK gives for business-to-business transactions; your contract can set a different rate instead.
- The rate
- 8% a year over Bank Rate on the 30 June or 31 December before the invoice fell overdue
- The interest
- Amount owed × rate × days late ÷ 365
- The fixed sum
- £40 under £1,000, £70 up to £9,999.99, £100 from £10,000
Take a £4,500 invoice due on 1 August 2026. It fell overdue on 2 August, so Bank Rate on 30 June 2026, 3.75%, sets its rate: 11.75% a year. On 10 October it's 70 days late: £4,500 × 11.75% × 70 ÷ 365 = £101.40 interest, plus the £70 fixed sum, £171.40 in all. Until it's paid, the interest grows by £1.45 a day.
Which Bank of England rate applies?
Bank Rate on the 30 June or 31 December just before interest starts to run, and it stays that rate for the invoice. The rate order sets interest at 8% a year “over the official dealing rate in force on the 30th June” for interest that starts to run from July to December, and on 31 December for January to June (SI 2002/1675, article 4). So a cut or rise in Bank Rate after an invoice falls overdue doesn't change its rate, and two invoices to the same client can carry different rates.
| Invoice overdue from | Bank Rate on | Statutory interest |
|---|---|---|
| 1 Jul 2026 to 31 Dec 2026 | : 3.75% | 11.75% a year |
| 1 Jan 2026 to 30 Jun 2026 | : 3.75% | 11.75% a year |
| 1 Jul 2025 to 31 Dec 2025 | : 4.25% | 12.25% a year |
| 1 Jan 2025 to 30 Jun 2025 | : 4.75% | 12.75% a year |
| 1 Jul 2024 to 31 Dec 2024 | : 5.25% | 13.25% a year |
| 1 Jan 2024 to 30 Jun 2024 | : 5.25% | 13.25% a year |
| 1 Jul 2023 to 31 Dec 2023 | : 5% | 13% a year |
| 1 Jan 2023 to 30 Jun 2023 | : 3.5% | 11.5% a year |
| 1 Jul 2022 to 31 Dec 2022 | : 1.25% | 9.25% a year |
| 1 Jan 2022 to 30 Jun 2022 | : 0.25% | 8.25% a year |
| 1 Jul 2021 to 31 Dec 2021 | : 0.1% | 8.1% a year |
| 1 Jan 2021 to 30 Jun 2021 | : 0.1% | 8.1% a year |
| 1 Jul 2020 to 31 Dec 2020 | : 0.1% | 8.1% a year |
| 1 Jan 2020 to 30 Jun 2020 | : 0.75% | 8.75% a year |
Bank Rate from the Bank of England's Bank Rate history, read on 28 October 2026. The next row is set by Bank Rate on 31 December 2026.
The fixed sum: £40, £70 or £100
Once interest starts to run on a late invoice, you're also owed a fixed sum for the cost of recovering it, once for each invoice. It's £40 for a debt under £1,000, £70 from £1,000 to £9,999.99, and £100 from £10,000 (section 5A of the Act). If your reasonable costs of recovering the debt are more, you can claim the difference too. So three late invoices of £800 carry £120 in fixed sums, where one invoice of £2,400 carries £70.
When is an invoice late?
The day after the payment date you agreed, or, if you agreed none, 30 days after your customer gets the invoice or you deliver the work, whichever is later. GOV.UK says an agreed payment date must usually be within 60 days between businesses and 30 days for public authorities; you can agree a longer period with a business if it's fair to both.
How do I claim it?
Ask for it in writing: GOV.UK's advice is to send a new invoice if you decide to add interest. Print the claim letter from the result above, or copy its link: it lists each invoice, its rate, the interest and the fixed sum, and what interest adds each day until you're paid. You can't claim statutory interest where your contract sets a different rate of interest.
Questions
Can I claim interest on several invoices at once?
Yes. Each invoice is its own debt: it carries its own rate, its own days late and its own fixed sum. Add each one above and print one letter for all of them.
Does the rate change when the Bank of England changes Bank Rate?
Not for an invoice that's already late. Its rate is fixed by Bank Rate on the 30 June or 31 December before it fell overdue, and stays until it's paid.
Is this the same as the late fee calculator's UK terms?
The same rates and fixed sums. The late fee calculator also shows how BillGrid adds them to an invoice: the fixed sum the day after it's due, then interest every 30 days, so a late payer sees one line a month. This page counts interest to the day.
How do I send this to my client?
Print the claim letter or copy the link under the result. The link opens this exact answer, dates included, so your client can check the figures.
Sources
Read on : GOV.UK, Late commercial payments; the Late Payment of Commercial Debts (Interest) Act 1998 and the rate order, SI 2002/1675 at legislation.gov.uk; the Bank of England's Bank Rate history. We add each new rate after 30 June and 31 December. This is general information, not legal advice.